Avoid reusing examples across independent pages

[jpmckinney]

Review (:file:|include}) (\.\./)?\.\./examples/ to check whether the examples/ folder matches the page.

If it doesn't (like amendments/tender.json being used in schema/merging, schema/records_reference and schema/packaging/record_package), then move it to a different directory or make a copy, as it's not expected that updating the amendments example could change the explanation on another page.

Do this once current examples-related PRs merged.

[jpmckinney]

I did a quick review now and I think it's the only one.